On Wed, Jan 23, 2019 at 07:21:57AM +0000, Kahola, Mika wrote:
> On Tue, 2019-01-22 at 21:09 +0200, Ville Syrjälä wrote:
> > On Tue, Jan 22, 2019 at 08:09:40PM +0200, Jani Nikula wrote:
> > > On Tue, 22 Jan 2019, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > > wrote:
> > > > On Tue, Jan 22, 2019 at 02:58:24PM +0200, Mika Kahola wrote:
> > > > > Avoid divide by zero warning on static analysis.
> > > > >
> > > > > Signed-off-by: Mika Kahola <mika.kahola@xxxxxxxxx>
> > > > > ---
> > > > > drivers/gpu/drm/i915/intel_pm.c | 6 ++++--
> > > > > 1 file changed, 4 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/i915/intel_pm.c
> > > > > b/drivers/gpu/drm/i915/intel_pm.c
> > > > > index 8b63afa3a221..6a8e8b3f44c2 100644
> > > > > --- a/drivers/gpu/drm/i915/intel_pm.c
> > > > > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > > > > @@ -3912,8 +3912,10 @@
> > > > > skl_ddb_get_pipe_allocation_limits(struct drm_i915_private
> > > > > *dev_priv,
> > > > > pipe_width = hdisplay;
> > > > > }
> > > > >
> > > > > - alloc->start = ddb_size * width_before_pipe /
> > > > > total_width;
> > > > > - alloc->end = ddb_size * (width_before_pipe +
> > > > > pipe_width) / total_width;
> > > > > + alloc->start = total_width == 0 ?
> > > > > + 0 : ddb_size * width_before_pipe / total_width;
> > > > > + alloc->end = total_width == 0 ?
> > > > > + 0 : ddb_size * (width_before_pipe + pipe_width)
> > > > > / total_width;
> > > >
> > > > Can't happen.
> I'd say it's very unlikely to happen but in theory possible. If we
> don't have any crtc_state enabled we end up having total_width = 0. In
> this case it probably won't matter what numbers we end up with alloc-
> >start and alloc->end.
The caller bails out early in that case:
if (!cstate->base.active) {
alloc->start = alloc->end = 0;
return 0;
}
>
> Anyway, this was something that caught my eye while looking into crc
> mismatch errors and static checker results.
>
> Like Jani said, warn is sufficient with this case.
>
> Cheers,
> Mika
>
> > >
> > > Yeah, it's about stfu the checker...
> >
> > Feels like the tip of an iceberg. How many more uglies are we going
> > to
> > have to add?
> >
> > >
> > > >
> > > > > }
> > > > >
> > > > > static unsigned int skl_cursor_allocation(int num_active)
> > > > > --
> > > > > 2.17.1
> > > > >
> > > > > _______________________________________________
> > > > > Intel-gfx mailing list
> > > > > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> > > > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > >
> > > --
> > > Jani Nikula, Intel Open Source Graphics Center
> >
> >
--
Ville Syrjälä
Intel
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
